Involves selecting samples based on chance events, ensuring each member of the population has an equal chance of selection
Sample
A subset of a larger population used to draw inferences about the entire population
Sampling Methods
Random Sampling
Stratified Random Sampling
Cluster (Area) Sampling
Systematic Sampling
Random Sampling
Every member of the population has a known and equal chance of being selected
Stratified Random Sampling
Population divided into mutually exclusive groups, and random samples are drawn from each group
Cluster (Area) Sampling
Population divided into groups, and a sample of the group is selected for interview
Systematic Sampling
Every nth case after a random selection is selected, providing simplicity and structure to the sampling process
Sampling Design
The technique or procedure used for selecting items as samples from the population or universe
Sample Size
Determined based on who will be surveyed, how many people will be surveyed, and how the sample should be chosen
Purpose: To understand the principles and techniques of non-probability sampling for qualitative research
Non-Probability Sampling
Involves selecting samples based on nonrandom criteria, where not every individual has an equal chance of inclusion
Types of Non-Probability Samples
Purposive Sampling
Snowball Sampling
Quota Sampling
Convenience Sampling
Purposive Sampling
Selects participants based on specific perspectives or criteria relevant to the study
Snowball Sampling
Participants are identified through referrals from initial participants, useful for studying stigmatized or hard-to-reach groups
Quota Sampling
Participants are selected to ensure representation across important categories with anticipated variation
Convenience Sampling
Participants are chosen based on convenience or accessibility, often used in exploratory research or by journalists for quick access to participants
Non-probability samples are suitable for exploratory and qualitative research, where the goal is not to make statistical inferences about the entire population but to develop initial understandings or insights
While non-probability samples offer convenience, they carry a higher risk of sampling bias and should be used cautiously for generalizing findings to larger populations
Statistics
Involves the collection, analysis, interpretation, and conclusion of data
Biostatistics
Applies statistical techniques to biomedical data for conclusions
Measurement scale is crucial in data collection, analysis, and presentation
Constant
A situation or value that does not change
Variable
A characteristic, number, or quantity that varies or differs
Independent Variable
A variable whose value affects another variable
Dependent Variable
A variable whose value may change due to the change in another variable
Moderator Variable
A variable that affects the cause-and-effect relationship between two other variables
Controlled Variable
A variable whose effect is controlled to isolate the relationship between other variables
Intervening Variable
A variable that may affect the relationship between other variables but is not measured or controlled
Nominal
Qualitative data assessed in terms of words or attributes
Ordinal
Qualitative data assessed in terms of rank order
Discrete
Quantitative data whose values cannot be expressed as decimals
Continuous
Quantitative data measured in values and can be quantified in decimals
Primary Data Collection
Data collected directly from research participants for the study
Secondary Data Collection
Data collected from published research papers for secondary research studies
Surveys
Conducted traditionally using paper-based or online methods, with closed-ended questions predominating
One-on-One Interviews
Traditionally face-to-face but now often conducted via telephone or online platforms, structured and extensive in collecting information
Data Collection Procedure
1. Define the Aim
2. Develop Operational Definitions
3. Choose Data Collection Techniques
4. Begin Data Collection
Data collection is foundational to research, requiring careful planning and execution to ensure the validity and reliability of the findings
Qualitative methods
Focus on gaining insights and understanding underlying reasons and motivations
Qualitative methods
Emerged due to the limitations of traditional quantitative methods in expressing human feelings and emotions